The Enstone squad, who finished fourth last year in the championship, is currently sixth in the standings 43 points down on fourth-placed McLaren.
At the last four races, Renault has scored points at one of the Grand Prix, with Daniel Ricciardo and Hulkenberg crossing the line in 7th and 10th respectively.
"The car was quite difficult to drive again today," Hulkenberg said at the Hungarian Grand Prix. "The balance didn't really work for us today so it was fighting with the front axle and the rear axle and we just didn't have the pace, but with these things you just can't expect too much.
"It's a tough one. It's quite below obviously our expectations and out targets so I think we need to ask ourselves some serious questions and review a couple of things internally but yeah, there's been far more lows than highs.
"[We need to look at] how we go about things. From the last eighteen months to the car to what we have been doing and the effect all this has. We just need to ask ourselves how we will go about things in the future.
"We need to make sure that whatever updates we bring forward will bring some yield and manage to bring us forward."
Hulkenberg's future at Renault is not yet certain, as his current contract with the team expires at the end of the season.
The German says he is still focused on Formula 1, and is not yet interested in making a full-time switch to a different series, such as Formula E.
“I’m not ready for Formula E yet," he said. "I like what I’m doing. It will obviously depend on the opportunities available, but for now, I’m focusing exclusively on Formula 1.”